JP2003043615A - Thermally developable photographic sensitive material, image recording method and processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermally developable photographic sensitive material having low contrast, a wide exposure latitude and excellent maximum density, minimum density and image quality of an image and to provide an image recording method and a processing method. SOLUTION: In the thermally developable photographic sensitive material containing a photosensitive silver halide emulsion, an organic silver salt, a reducing agent and a binder, photosensitive silver halide grains in the photosensitive silver halide emulsion are formed independently of the organic silver salt, two or more groups of photosensitive silver halide grains different from each other in average grain size are contained and a compound of formula (1) is contained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermographic material (hereinafter also simply referred to as a photothermographic material, a photographic photosensitive material, a photosensitive material), an image recording method and a processing method.

[0002]

2. Description of the Related Art Conventionally, in the fields of printing plate making and medical treatment, a waste liquid caused by wet processing of an image forming material has been a problem in terms of workability. Weight loss is strongly desired.

Techniques for preventing the generation of treatment waste liquid include:
Examples thereof include a photothermographic material which forms a photographic image by using a photothermographic method.

Photothermographic materials are disclosed, for example, in US Pat.
152,904, 3,457,075, D.I. “Dry Silver Photographic Material by Morgan” Dry Silver Photographic
Material "or D.I. H. Clostavale (Kl
Osterboer, "Thermal Processed Silver System (Thermally Processed)
Silver Systems "(Imaging Processes and Materials (Imaging)
Processes and Materials)
Nablette Eighth Edition, Sturg
e), V. Wallworth, A.S.
Edited by Shepp, p. 279, 1989.
, An organic silver salt, a catalytically active amount of a photocatalyst (eg, silver halide), and a reducing agent, usually in a dispersed state in an (organic) binder matrix,
When exposed to a high temperature (for example, 80 ° C. or higher) after exposure, silver is produced through a redox reaction between a reducible silver source (which functions as an oxidizing agent) and a reducing agent. This redox reaction is Since the latent image generated by exposure is accelerated by the catalytic action, an image is formed corresponding to the exposure.

In a system using such an image forming process, the number of developable photosensitive silver halide grains, that is, the number of silver points is an important factor for sensitivity and maximum density.

Theoretically, the sensitivity increases as the grain size of the photosensitive silver halide grains increases, but fog tends to occur during the dispersion process of the organic silver salt, and the light resistance deteriorates. Such a problem occurred.

When the particle size of the photosensitive silver halide grains is too small, the sensitivity is lowered and a desired density cannot be obtained.

Further, in the photothermographic material, the image contrast is higher than that of the conventional wet-processed silver halide photographic material, and the characteristic curve γ when the desired maximum density is obtained.
The (gamma) value is 2.5 or more in most cases.

Further, recently, as the use of the photothermographic material has expanded, the contrast is low especially in the medical field,
Wide exposure latitude has been demanded.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a photothermographic material having a low contrast, a wide exposure latitude, and excellent maximum density, minimum density and image quality of an image.
An object is to provide an image recording method and a processing method.

[0011]

The above object of the present invention can be achieved by the following constitutions.

1. Photosensitive silver halide emulsion, organic silver salt,
In a photothermographic material containing a reducing agent and a binder, two or more kinds of photosensitive silver halide grains in the photosensitive silver halide emulsion are formed independently of the organic silver salt and have different average grain sizes. 2. A photothermographic material, containing the photosensitive silver halide grains of 1. and a compound represented by the general formula (1).

2. The maximum particle size of the two or more types of photosensitive silver halide particles having different average particle sizes is 0.06 μm.
˜0.09 μm, and the minimum particle size is 0.03 μm˜
2. The heat-developable photographic light-sensitive material as described in 1 above, which is 0.05 μm.

3. Total silver amount is 0.5 g / m ^{2 to} 1.5 g /
^{3. The} photothermographic material according to 1 or 2 above, wherein the photothermographic material is m ² .

4. The exposure wavelength is 770 nm to 11 using the photothermographic material according to any one of 1 to 3 above.
An image recording method comprising exposing with a scanning laser beam of 00 nm.

5. 5. The image recording method as described in 4 above, wherein exposure is performed by a laser beam scanning exposure device in which the scanning laser beam is a longitudinal multi-beam.

6. 6. The image recording method as described in 4 or 5 above, wherein exposure is performed by a laser beam scanning exposure device in which an angle formed by the scanning laser beam is not substantially vertical.

7. 4. A processing method comprising processing the photothermographic material according to any one of 1 to 3 above at a developing temperature of 100 to 150 ° C.

The present invention will be described in more detail below. The compound of the general formula (1) of the present invention is an excellent supersensitizer.

The compound represented by the general formula (1) will be described in detail. The divalent linking group consisting of an aliphatic hydrocarbon group represented by T ₃₁ is a linear, branched or cyclic alkylene group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and further preferably Represents a carbon number of 1 to 12), an alkenyl group (preferably a carbon number of 2 to 20, more preferably a carbon number of 2 to 16, and further preferably a carbon number of 2 to 12),
Alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and further preferably 2 to 12 carbon atoms)
And may have a substituent. For example, as the aliphatic hydrocarbon group, a linear, branched or cyclic alkyl group (preferably having a carbon number of 1 to 20, more preferably having a carbon number of 1) is used.
To 16, more preferably 1 to 12 carbon atoms, an alkenyl group (preferably 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, still more preferably 2 to 12 carbon atoms), an alkynyl group (preferably carbon number). 2 to 20, more preferably 2 to 16 carbon atoms, and further preferably 2 to 12 carbon atoms,
The aryl group is a monocyclic or condensed-ring aryl group having 6 to 20 carbon atoms (for example, phenyl, naphthyl and the like, preferably phenyl), and the heterocyclic group is a 3- to 10-membered saturated group, Unsaturated heterocyclic groups (eg,
2-thiazolyl, 1-piperazinyl, 2-pyridyl, 3
-Pyridyl, 2-furyl, 2-thienyl, 2-benzimidazolyl, carbazolyl, etc.), and the hetero ring in these groups may be a single ring or may form a condensed ring with another ring. .

Each of these groups may have a substituent at any position. For example, an alkyl group (including a cycloalkyl group and an aralkyl group, preferably having 1 to 20 carbon atoms,
More preferably, it has 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms, such as methyl, ethyl, n-propyl,
iso-propyl, n-butyl, tert-butyl, n
-Heptyl, n-octyl, n-decyl, n-undecyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, benzyl, phenethyl and the like. ), An alkenyl group (preferably having 2 to 20 carbon atoms,
It preferably has 2 to 12 carbon atoms, and particularly preferably 2 to 8 carbon atoms, and examples thereof include vinyl, allyl, 2-butenyl, and 3-pentenyl groups. ), An alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably 2 to 8 carbon atoms, and examples thereof include propargyl and 3-pentynyl groups). Group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and particularly preferably 6 to 30 carbon atoms)
12 and examples thereof include phenyl, p-tolyl, O-aminophenyl, and naphthyl groups. ), An amino group (preferably having a carbon number of 0 to 20, more preferably a carbon number of 0 to 10, and particularly preferably a carbon number of 0 to 6), for example, amino, methylamino, ethylamino, dimethylamino, diethylamino, diphenylamino, Each group such as dibenzylamino, etc.), an imino group (preferably having 1 to 20 carbon atoms, more preferably 1 to 18 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include methylimino, ethylimino, Each group such as propylimino, phenylimino, etc.), an alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, for example, methoxy, Each group such as ethoxy and butoxy is exemplified.), An aryloxy group (preferably having 6 to 20 carbon atoms, more preferably having 6 to 6 carbon atoms). 6, particularly preferably 6 to 12 carbon atoms,
Examples thereof include phenyloxy and 2-naphthyloxy groups. ), An acyl group (preferably having 1 to 2 carbon atoms)
0, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, acetyl, benzoyl,
Each group such as formyl and pivaloyl can be mentioned. ), An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 2 carbon atoms).
12 and examples thereof include groups such as methoxycarbonyl and ethoxycarbonyl. ), An aryloxycarbonyl group (preferably having a carbon number of 7 to 20, more preferably a carbon number of 7 to 16, particularly preferably a carbon number of 7 to 10, and examples thereof include a phenyloxycarbonyl group) and an acyloxy group. (Preferably having 1 to 20 carbon atoms,
It preferably has 1 to 16 carbon atoms, and particularly preferably 1 to 10 carbon atoms, and examples thereof include acetoxy and benzoyloxy groups. ), An acylamino group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 10 carbon atoms, and examples thereof include acetylamino and benzoylamino groups).
Alkoxycarbonylamino group (preferably having 2 to 2 carbon atoms)
20, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 12 carbon atoms, and examples thereof include a methoxycarbonylamino group. ), An aryloxycarbonylamino group (preferably having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, and examples thereof include a phenyloxycarbonylamino group). Sulfonylamino group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms, and examples thereof include methanesulfonylamino and benzenesulfonylamino).
Sulfamoyl group (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, and particularly preferably 0 to 12 carbon atoms).
And examples thereof include sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, and phenylsulfamoyl groups. ), A carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include carbamoyl, methylcarbamoyl, diethylcarbamoyl, and phenylcarbamoyl groups. , An alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms,
Examples include groups such as methylthio and ethylthio. ), An arylthio group (preferably having 6 to 20 carbon atoms,
It preferably has 6 to 16 carbon atoms, and particularly preferably 6 to 12 carbon atoms, and examples thereof include a phenylthio group. ), A sulfonyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 carbon atoms).
To 12 and examples thereof include groups such as methanesulfonyl and tosyl. ), A sulfinyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms, and examples thereof include methanesulfinyl and benzenesulfinyl groups). Ureido group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 1 carbon atoms)
12 and examples thereof include groups such as ureido, methylureido, and phenylureido. ), A phosphoric acid amide group (preferably having a carbon number of 1 to 20, more preferably a carbon number of 1 to 16 and particularly preferably a carbon number of 1 to 12), and examples thereof include diethylphosphoric acid amide and phenylphosphoric acid amide. , A hydroxy group, a mercapto group,
Halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, sulfino group, carboxyl group, phosphono group, phosphino group, nitro group, hydroxamic acid group, hydrazino group, heterocyclic group ( Examples thereof include imidazolyl, benzimidazolyl, thiazolyl, benzothiazolyl, carbazolyl, pyridyl, furyl, piperidyl, morpholino, etc.) and the like.

Of the above groups, a salt-forming group such as a hydroxy group, a mercapto group, a sulfo group, a sulfino group, a carboxyl group, a phosphono group and a phosphino group may be a salt. These substituents may be further substituted.

When there are two or more substituents, they may be the same or different. As the substituent, an alkyl group, an aralkyl group, an alkoxy group, an aryl group, an alkylthio group, an acyl group, an acylamino group, an imino group, a sulfamoyl group, a sulfonyl group, a sulfonylamino group,
Ureido group, amino group, halogen atom, nitro group, heterocyclic group, alkoxycarbonyl group, hydroxy group, sulfo group, carbamoyl group, carboxyl group, more preferably alkyl group, alkoxy group, aryl group, alkylthio group, acyl Group, acylamino group, imino group, sulfonylamino group, ureido group, amino group, halogen atom, nitro group, heterocyclic group, alkoxycarbonyl group,
Hydroxy group, sulfo group, carbamoyl group, carboxyl group, more preferably alkyl group, alkoxy group, aryl group, alkylthio group, acylamino group, imino group, ureido group, amino group, heterocyclic group, alkoxycarbonyl group, hydroxy A group, a sulfo group, a carbamoyl group, and a carboxyl group. The amidino group includes those having a substituent, and examples of the substituent include an alkyl group (methyl, ethyl, pyridylmethyl, benzyl,
Phenethyl, carboxybenzyl, aminophenylmethyl, etc.), aryl groups (phenyl, p-tolyl, naphthyl, o-aminophenyl, o-methoxyphenyl, etc.), heterocyclic groups (2-thiazolyl, 2- Pyridyl,
3-pyridyl, 2-furyl, 3-furyl, 2-thieno,
2-imidazolyl, benzothiazolyl, carbazolyl and the like) and the like.

The aliphatic hydrocarbon group, the aryl group and the heterocyclic group represented by Ra, Rb, Rc and Rd are the same as the aliphatic hydrocarbon group, the aryl group and the heterocyclic group mentioned in the above T ₃₁ . The same groups can be mentioned, and the preferred range is also the same.

The acyl group represented by Ra, Rb, Rc and Rd is an aliphatic or aromatic group having 1 to 12 carbon atoms, and specific examples thereof include acetyl, benzoyl, formyl and pivaloyl groups. To be

The nitrogen-containing heterocyclic group formed by combining Ra and Rb, Rc and Rd, Ra and Rc or Rb and Rd is a 3- to 10-membered saturated or unsaturated heterocyclic group (the heterocyclic group). Examples of the hetero ring of the group include a piperidine ring, a piperazine ring, an acridine ring, a pyrrolidine ring, a pyrrole ring, a morpholine ring and the like).

Examples of the divalent linking group represented by J ₃₁ containing at least one oxygen atom, sulfur atom or nitrogen atom include the following. Also, a combination of these may be used.

[0028]

[Chemical 2]

Here, Re and Rf are each the above-mentioned R.
It is synonymous with the contents defined in a to Rd.

The aromatic hydrocarbon group represented by Ar is preferably an aromatic hydrocarbon group having 6 to 30 carbon atoms, more preferably a monocyclic or condensed ring aryl group having 6 to 20 carbon atoms, for example, phenyl. , Each group such as naphthyl,
Particularly preferred is a phenyl group. The aromatic heterocyclic group represented by Ar is a 5- to 10-membered unsaturated heterocyclic group containing at least one atom selected from N, O and S, and the heterocycle in these groups is a monocyclic ring. Or may form a condensed ring with another ring. The heterocycle in such a heterocyclic group is preferably a 5- or 6-membered aromatic heterocycle and its benzo-condensed ring, and more preferably a 5- or 6-membered aromatic heterocycle containing a nitrogen atom and its benzo-condensed ring. A ring, more preferably 1 to 2 nitrogen atoms.
It is a 5- or 6-membered aromatic heterocycle containing atoms and its benzo-fused ring.

Specific examples of the hetero ring of the hetero ring group include:
For example, thiophene, furan, pyrrole, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, indazole,
Purine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benzothiazole, benzothiazoline, benzotriazole, tetra Each ring such as Zaindene and carbazole may be mentioned.

Of these, the hetero ring of the hetero ring group is preferably imidazole, pyrazole, pyridine, pyrazine, indole, indazole, thiadiazole,
Oxadiazole, quinoline, phenazine, tetrazole, thiazole, oxazole, benzimidazole,
Benzoxazole, benzothiazole, benzothiazoline, benzotriazole, tetrazaindene, carbazole ring, more preferably imidazole, pyridine, pyrazine, quinoline, phenazine, tetrazole, thiazole, benzoxazole, benzimidazole, benzothiazole, benzothiazoline. , Benzotriazole, carbazole and the like.

The aromatic hydrocarbon group and aromatic heterocyclic group represented by Ar may have a substituent, and the substituent is, for example, the same as the group mentioned as the substituent of T _31. The preferred range is also the same. These substituents may be further substituted, and when there are two or more substituents, they may be the same or different.
The group represented by Ar is preferably an aromatic heterocyclic group.

Specific examples of the acid anion as the ion necessary for offsetting the charge in the molecule represented by M ₃₁ include, for example, halogen ion (eg, chlorine ion, bromine ion,
Iodine ion), p-toluenesulfonate ion, perchlorate ion, boron tetrafluoride ion, sulfate ion, methylsulfate ion, ethylsulfate ion, methanesulfonate ion, trifluoromethanesulfonate ion and the like.

Specific examples of the compound represented by the general formula (1) are shown below, but the invention is not limited thereto.

[0036]

[Chemical 3]

[0037]

[Chemical 4]

[0038]

[Chemical 5]

[0039]

[Chemical 6]

[0040]

[Chemical 7]

[0041]

[Chemical 8]

As the compound represented by the general formula (1) of the present invention, a commercially available compound may be used, or a compound synthesized by a known method may be used. For example, edited by The Chemical Society of Japan, New Experimental Chemistry Course, Vol. 14 (III), pages 1739-1741 (1
978) and the like.

The compound represented by the general formula (1) of the present invention can be added to either the photosensitive layer or the non-photosensitive layer in the photothermographic material, but the photosensitive layer is preferable.

The addition amount of the compound represented by the general formula (1) of the present invention varies depending on the desired purpose, but is usually 10 ⁻⁴ to 1 mol, preferably 10 ^{−3 to} 0.3 mol per 1 mol of Ag.
It is more preferable to add 10 ^{−3 to} 0.1 mol. The compounds of general formula (1) may be used alone or in combination of two or more.

The compound represented by the general formula (1) of the present invention is water or a suitable organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohol), ketones (acetone, methyl ethyl ketone),
It can be used by dissolving it in dimethylformamide, dimethylsulfoxide, methylcellosolve and the like.

Further, by a well-known emulsification dispersion method, oils such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, and an auxiliary solvent such as ethyl acetate or cyclohexanone are used to dissolve and mechanically dissolve them. An emulsified dispersion can be prepared and used.

Alternatively, the powder can be used by dispersing it in water by a ball mill, colloid mill, sand grinder mill, manton-goulin, microfluidizer or ultrasonic wave by a method known as a solid dispersion method. Further, a dispersion aid may be used when dispersing the solid fine particles.

The photosensitive silver halide grain of the present invention functions as an optical sensor of a photothermographic material, in order to suppress white turbidity after image formation in a photothermographic system and to obtain good image quality. The average grain size of the photosensitive silver halide grains is preferably small, and therefore the average grain size of the photosensitive silver halide grains is preferably 0.1 μm or less, more preferably 0.01 μm to 0.1 μm, and particularly preferably 0 μm. It is 0.03 μm to 0.09 μm. The average grain size as used herein refers to the length of the edges of the photosensitive silver halide grains when the photosensitive silver halide grains are cubic or octahedral so-called normal crystals. When it is not a normal crystal, for example, in the case of spherical, rod-shaped or tabular grains, it means the diameter when considering a sphere equivalent to the volume of the photosensitive silver halide grain.

[0049] Also, it is characterized in that the total amount of silver photothermographic material of the present invention is ^{0.5g / m 2 ~1.5g / m 2} . If it is less than 0.5 g / m ² , sufficient density cannot be obtained, and if it exceeds 1.5 g / m ² , fog increases, which is not preferable.

The photosensitive silver halide grains of the present invention are preferably monodisperse. The monodispersion here means that the degree of monodispersion obtained by the following formula is usually 40% or less.
It is preferably 30% or less, more preferably 0.1%
~ 20% particles.

Monodispersity = (standard deviation of grain size) / (average value of grain size) × 100 The shape of the photosensitive silver halide grain is not particularly limited, but the proportion occupied by Miller index [100] planes Is preferably high, so this ratio is 5
It is preferably 0% or more, more preferably 70% or more, and particularly preferably 80% or more. Miller index [10
The ratio of the [0] plane is measured by T.O., which utilizes the adsorption dependence of the [111] plane and the [100] plane in the adsorption of the photosensitive dye. Tani,
J. Imaging Sci. , 29, 165 (198
It can be determined by 5).

Another preferred form of the photosensitive silver halide grain is a tabular grain. The tabular grains referred to herein mean an aspect ratio = r / h when the square root of the projected area is rμm and the vertical thickness is hμm.
Means 3 or more. Among them, the aspect ratio is preferably 3 to 50. The particle size is preferably 0.1 μm or less, and more preferably 0.01 μm to 0.08 μm.
Is preferred.

These are US Pat. No. 5,264,337,
No. 5,314,798, No. 5,320,958, etc., and the desired tabular grains can be easily obtained.

In the present invention, when these tabular grains are used, the sharpness of the image is further improved. The halogen composition is not particularly limited and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide and silver iodide.

However, the photosensitive silver halide grains of the present invention preferably have silver iodobromide grains containing 0.5 mol% or more of iodine, more preferably 0.7 mol%.
~ 5 mol%. When the iodide content is less than 0.5 mol%, it is difficult to obtain the necessary sensitivity, and when the iodide content exceeds 5 mol%, the developability deteriorates and the gradation becomes soft, which is not preferable.

The photographic emulsions used in the present invention are described in P. Gl
afkides Chimieet Physiqu
e Photographique (Paul Mon)
tel, 1967), G.I. F. By Duffin
Photographic Emulsion Chem
istry (published by The Focal Press, 19
66), V.I. L. By Zelikman et al
Making and Coating Photog
radical Emulsion (TheFocal
It can be prepared using the method described in Press, 1964).

That is, any of the acidic method, the neutral method, the ammonia method and the like may be used, and the method of reacting the soluble silver salt with the soluble halogen salt may be any of a one-sided mixing method, a simultaneous mixing method and a combination thereof. May be used. The silver halide grains may be added to the image forming layer in any manner, with the silver halide grains being located in close proximity to the reducible silver source.

The present invention is characterized in that two or more kinds of photosensitive silver halide grains having different average grain sizes are used by independently mixing with an organic silver salt and previously formed. A part or the whole of which is converted into a photosensitive silver halide grain can be used together.

That is, the heat-developable photographic light-sensitive material of the present invention is formed independently of an organic silver salt and has a different average particle size.
Two or more types of photosensitive silver halide grains having different average grain sizes can be obtained by mixing them in any step from the formation of the organic silver salt to the interposing of the photosensitive layer coating solution on the support. Characteristic silver halide grains are contained, and it is preferable that the support is sufficiently mixed just before coating and then coated.

Preferably, two or more kinds of photosensitive silver halide grains having different average grain sizes have a maximum grain size of 0.06 μm to 0.09 μm and a minimum grain size of 0.06 μm to 0.09 μm. It is from 03 μm to 0.05 μm.

Generally, the photosensitive silver halide grains are preferably contained in an amount of 0.75 to 30% by mass based on the organic silver salt.

The photosensitive silver halide grains of the present invention preferably contain metal ions belonging to Groups 6 to 11 of the periodic table. As the metal, W, Fe, Co, N
i, Cu, Ru, Rh, Pd, Re, Os, Ir, P
t and Au are preferred.

These metal ions can be introduced into the silver halide in the form of metal complexes or metal complex ions. As the metal complex or metal complex ion, a hexacoordinated metal complex represented by the following general formula is preferable.

[0064] Formula [ML _6] ^m wherein the transition metal M is selected from 6-11 group elements of the periodic table, L is a ligand, m is 0, -, 2-, 3- or 4-
Represents Specific examples of the ligand represented by L include halides (fluorides, chlorides, bromides and iodides), cyanides, cyanates, thiocyanates, selenocyanates, tellurocyanates, azides and aco. Examples include ligands, nitrosyl, thionitrosyl, and the like, with preference given to ako, nitrosyl, thionitrosyl, and the like. When an aco ligand is present, it preferably occupies one or two of the ligands. L may be the same or different.

As M, rhodium (Rh), ruthenium (Ru), rhenium (Re), iridium (Ir) and osmium (Os) are preferable, and specific examples of the transition metal complex ion containing them include [RhCl ₆ ] ^3- [RuCl ₆ ] ^3- [ReCl ₆ ] ^3- [RuBr ₆ ] ^3- [OsCl ₆ ] ^3- [IrCl ₆ ] ^4- [Ru (NO) Cl ₅ ] ^2- [RuBr ₄ (H ₂ O )] ^2- _{[Ru (NO) (H 2 O} ) Cl 4 ] ^- [RhCl ₅ (H ₂ O)] ^2-, [Re (NO) Cl _5] ^2- [Re (NO) (CN) _5] ^2- [Re (NO) Cl (CN) ₄ ] ^2- [Rh (NO) ₂ Cl ₄ ] ^- [Rh (NO) (H ₂ O) Cl ₄ ] ^- [Ru (NO) (CN) ₅ ] ^{2 -} [Fe (CN) _6] ^3- [Rh (NS) Cl _5] ^2- [Os (NO) Cl _5] ^2- [Cr (NO) Cl _5] ^2- [ Re (NO) Cl ₅ ] ^- [Os (NS) Cl ₄ (TeCN)] ^2- [Ru (NS) Cl ₅ ] ^2- [Re (NS) Cl ₄ (SeCN)] ^2- [Os (NS) Cl (SCN) ₄ ] ^2- [Ir (NO) Cl ₅ ] ^2- [Ir (NS) Cl ₅ ] ^{2- and the} like.

The above-mentioned metal ions or metal complex ions may be used alone, or two or more kinds of the same kind of metal and different kinds of metal may be used in combination. The content of these metal ions or metal complex ions is generally 1 × 10 ⁻⁹ to 1 × 10 ⁻² mol, and preferably 1 × 10 ⁻⁸ to 1 mol per 1 mol of the photosensitive silver halide grains. It is 1 × 10 ⁻⁴ mol.

The compounds providing these metals are preferably added at the time of formation of the photosensitive silver halide grains and incorporated into the silver halide grains. Preparation of the photosensitive silver halide grains, that is, nucleation and growth. It may be added at any stage before or after physical ripening or chemical sensitization, but it is particularly preferable to add at the stage of nucleation, growth or physical ripening, and further at the stage of nucleation or growth. Is preferred, and most preferably, it is added at the stage of nucleation.

Upon addition, it may be added dividedly over several times, and it may be added uniformly in the photosensitive silver halide grains. JP-A-63-29603, JP-A-2- No. 306236, No. 3-167545, No. 4
-76534, 6-110146, 5-273.
As described in Japanese Patent No. 683, etc., it may be contained by having a distribution inside the particles, and preferably, it has a distribution inside the particles.

These metal compounds can be added after being dissolved in water or a suitable organic solvent (eg alcohols, ethers, glycols, ketones, esters, amides). A method of adding an aqueous solution of the powder of 1) or an aqueous solution in which a metal compound and NaCl, KCl are dissolved together to a water-soluble silver salt solution or a water-soluble halide solution during grain formation, or a silver salt solution and a halide solution. When mixed at the same time, added as a third aqueous solution, a method of preparing photosensitive silver halide grains by a method of simultaneous mixing of three liquids, and a method of adding a necessary amount of an aqueous solution of a metal compound to a reaction vessel during the grain formation. Alternatively, at the time of preparation of the photosensitive silver halide grains, another photosensitive silver halide grain to which metal ions or complex ions have been previously doped is added and dissolved. There is a method and the like. In particular, a method of adding an aqueous solution of a powder of a metal compound or an aqueous solution in which a metal compound and NaCl or KCl are dissolved together to a water-soluble halide solution is preferable.

When added to the particle surface, a necessary amount of an aqueous solution of the metal compound may be added to the reaction vessel immediately after the particle formation, during or during physical ripening, or at the end of chemical ripening.

The photosensitive silver halide grains can be desalted by washing with water by a method known in the art such as a noodle method and a flocculation method. In the present invention, it may or may not be desalted. Good.

The photosensitive silver halide grain of the present invention is chemically sensitized by using an organic sensitizer containing a chalcogen atom in the process of producing the photothermographic material in the absence of an oxidizing agent. It is preferably applied.

As the organic sensitizer containing a chalcogen atom, which is preferably used in the present invention, there is disclosed JP-A-60-150.
046, JP-A-4-109240, JP-A 11-2
Organic sensitizers having various structures disclosed in 18874 and the like can be used.

The atomic group containing a group capable of adsorbing to silver halide in the present invention includes an atomic group having a mercapto group (for example, mercaptooxadiazole, mercaptotetrazole, mercaptotriazole, mercaptodiazole, mercaptothiazole, mercaptothiadiazole). , Mercaptooxazole, mercaptoimidazole, mercaptobenzothiazole, mercaptobenzoxazole, mercaptobenzimidazole, mercaptotetrazaindene, mercaptopyridyl, mercaptoquinolyl, 2-mercaptopyridyl, mercaptophenyl, mercaptonaphthyl, etc.), a thion group Atom group having (for example, thiazoline-2-thione, oxazoline-2-thione, imidazoline-2-thione, benzothiazoline-2-thion Atom, benzimidazoline-2-thione, thiazolidine-2-thione, etc.), an atom group forming imino silver (for example, triazole, tetrazole, benzotriazole, hydroxyazaindene, benzimidazole, indazole, etc.), atom having an ethenyl group And the like (eg, 2- [N- (2-propynyl) amino] benzothiazole, N- (2-propynyl) carbazole, etc.) and the like.

In the present invention, the compound having an unstable chalcogen atom site means a compound which forms chalcogen silver in the presence of silver nitrate. The chalcogen atom means a sulfur atom, a selenium atom and a tellurium atom.

Specific examples of the atom group containing an unstable sulfur moiety include an atom group having a thiourea group (for example, N, N'-
Diethylthiourea, N-ethyl-N '-(2-thiazolyl) thiourea, N, N-dimethylthiourea, N-phenylthiourea, etc.), thioamide group-containing atomic groups (eg, thiobenzamide, thioacetamide, etc.), polysulfides , An atom group having a phosphine sulfide group (for example, bis (pentafluorophenyl) phenylphosphine sulfide, diethylphosphine sulfide, dimethylphenylphosphine sulfide, etc.), an atom group having a thioxoazolidinone group (for example, ethylrhodamine, 5 -Benzylidene-3-ethylrhodonine, 1,3
-Diphenyl-2-thiohydantoin, 3-ethyl-4
-Oxooxazolidine-2-thione and the like).

Specific examples of the atom group containing an unstable selenium moiety include an atom group having a selenourea group (for example, N, N
-Dimethylselenourea, selenoureas, N-acetyl-
N, N'-diethylselenourea, N-trifluoroacetyl-N ', N'-dimethylselenourea, N-ethyl-
N '-(2-thiazolyl) selenourea, N, N'-diphenylselenourea, etc.), an atom group having a selenoamide group (for example, N-methyl-selenobenzamide, N-phenyl-selenobenzamide, N-ethyl-seleno). Benzamide, etc.), an atom group having a phosphine selenide group (for example, triphenylphosphine selenide, diphenyl-
(Pentafluorophenyl) phosphine selenide, tris (m-chlorophenyl) phosphine selenide, etc.), an atom group having a selenophosphate group (for example, tris (p-tolyl) selenophosphate etc.), an atom group having a selenoester group ( For example, p-methoxyselenobenzoic acid (= O) isopropyl ester, selenobenzoic acid (= Se) -3'-oxobutyl ester, p-methoxyselenobenzoic acid (= S)
e) each group such as 3′-oxocyclohexyl ester) and an atom group having a selenide group (for example, bis (2,2
6-dimethoxybenzoyl) selenide, bis (n-butoxycarbonyl) selenide, bis (benzyloxycarbonyl) selenide, bis (N, N-dimethylcarbamoyl) selenide, etc.), an atom group having a triselenane group (for example, 2 , 4,6-Tris (p-methoxyphenyl) triselenane, etc.), an atom group having a selenoketone group (for example, 4-methoxyselenoacetophenone, 4,4
-Methoxyselenobenzophenone, etc.) and the like.

Specific examples of the atom group containing an unstable tellurium moiety include an atom group having a phosphine telluride group (eg, butyl-di-isopropylphosphine telluride, triscyclohexylphosphine telluride) and a tellurourea group. Atomic group (for example, N, N'-diethyl-
N, N'-diethylene tellurourea, N, N'-dimethylene-N, N'-dimethyl tellurourea, etc., an atom group having a telluroamide group (for example, N, N-dimethyl-tellobenzamide, N, N-tetra) Methylene- (p-tolyl) tellurobenzamide and the like), an atomic group having a tellurophosphate group (for example, tris (p-tolyl) tellurophosphate, trisbutyl tellurophosphate, etc.), an atomic group having a tellurophosphoric amide group (for example, Hexamethyl tellurophosphoric amide and the like).

Other atom groups having unstable selenium and tellurium moieties are disclosed in JP-A-4-25832 and JP-A-4-25832.
-109240, 4-147250, 4-33
043, 5-40324, 5-24332,
5-24333, 5-303157, 5-3
06268, 5-306269, 6-2757.
No. 3, No. 6-43576, No. 6-75328, No. 6
-17528, 6-180478 and 6-175.
No. 29, No. 6-208184, No. 6-208186
No. 6, No. 6-317867, No. 7-92599, No. 7
-98483, 7-104415, 7-140
It can be selected from the compound group disclosed in No. 579, No. 7-301880 and the like.

As the compound having a group capable of adsorbing to silver halide and an unstable chalcogen atom site in the molecule, a compound represented by the following general formula [C] is preferably used.

[0081]

[Chemical 9]

In the general formula [C], A ¹ represents an atom group containing a group capable of adsorbing to silver halide, L ¹ represents a divalent linking group, Z ¹ represents an atom containing an unstable chalcogen atom site. And W ¹ , W ² and W ³ represent a carboxylic acid group, a sulfonic acid group, a sulfinic acid group, a phosphoric acid group, a phosphorous acid group and a boric acid group. m1 represents 0 or 1, n1 represents an integer of 1 to 3, and L1, L2, and L3 each represent an integer of 0 to 2.

The divalent linking group represented by L ¹ is a group composed of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, a sulfur atom or the like, and specifically, has 1 to 20 carbon atoms.
Alkylene group (for example, each group such as methylene, ethylene, propylene, and hexylene), an arylene group (for example,
Each group such as phenylene and naphthylene), -CONR _1- ,
_{-SO 2 NR 2 -, - O} -, - S -, - NR 3 -, - NR 4
_{CO -, - NR 5 SO 2} -, - NR 6 CONR 7 -, - CO
Examples include —O—, —O—CO—, —CO— and the like, and groups in which a plurality of these groups are linked.

R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ and R ₇ each represent a hydrogen atom, an aliphatic group, an alicyclic group, an aromatic group or a heterocyclic group.

The amount of chalcogen compound used varies depending on the chalcogen compound used, the photosensitive silver halide grains, the chemical sensitizing environment, etc., but is 10 ^-8 to 10 ^-2 mol per mol of the photosensitive silver halide grains. Preferably, more preferably 10 ⁻⁷ to 10 ⁻³ mol is used.

The chemical sensitizing environment in the present invention is not particularly limited, but pAg is preferably 6 to 11, more preferably 7 to 10, and pH is preferably 4 to 10 and more preferably 5 to 8. , The temperature is 40 ° C to 90
C is preferable, and more preferably 45 to 80 ° C.

In the sensitizing method used in the present invention, the photosensitive silver halide grain is an organic sensitizer containing a chalcogen atom under the condition that an oxidizing agent contained in the process of producing a photothermographic material does not exist. Chemically sensitized using an agent is disclosed in US Pat. No. 5,891,615.
Unlike the method of performing chemical sensitization under the condition of coexisting an oxidant such as romide hydrobromide, it is preferable to first perform the chemical sensitization with an organic sensitizer having a chalcogen atom under the condition that no oxidant is present. In the subsequent step, a method of adding an oxidant for the purpose other than sensitization such as fog suppression is preferable, and the conditions are controlled so that chemical sensitization is not substantially added by the addition of the oxidant. The method performed below is preferable.

In order to obtain controlled conditions so that chemical sensitization is not substantially added by the addition of the oxidant, the organic sensitizer preferably used in the present invention is chemically sensitized. In the sensitizing step, the reaction is substantially 100%, or the unreacted organic sensitizer is removed in a water washing step or the like, or the organic sensitizer is decomposed by an oxidizer having no sensitizing effect. Or it must be removed afterwards.

The photosensitive silver halide grains to be chemically sensitized according to the present invention are formed under the condition that an organic silver salt does not exist, but by reacting with a halogen ion in the presence of an organic silver salt. Similarly, the silver halide formed may be chemically sensitized.

In the present invention, it is particularly preferable to use a sensitizing dye having a spectral sensitivity in the infrared. Infrared spectral sensitizing dyes preferably used in the present invention include, for example, US Pat. Nos. 4,536,473 and 4,51.
Infrared spectral sensitizing dyes disclosed in 5,888, 4,959,294 and the like can be mentioned.

These sensitizing dyes may be used alone, or a combination thereof may be used, and the combination of sensitizing dyes is often used particularly for the purpose of supersensitization. Along with the sensitizing dye, a dye having no spectral sensitizing effect itself or a substance that does not substantially absorb visible light and exhibits supersensitization may be included in the emulsion.

Since the photosensitivity is particularly high when supersensitized, the printout silver after development tends to be large unless the reducing agent is deactivated, and the present invention is particularly effective. Further, when infrared sensitized, the infrared sensitizing dye further has a redox potential capable of reducing silver halide or an organic silver salt to some extent. In the presence of a reducing agent capable of reducing the organic silver salt of, the fog silver is likely to form silver clusters.

The produced silver clusters also act as catalyst nuclei to induce fog, so that the storage stability is deteriorated when stored in a dark place, or when printed out in a bright place after development. Phenomena such as silver becoming larger occur. Further, since the infrared sensitive material has sensitivity up to the heat radiation region outside the visible light range, it is effective for increasing the printout silver due to the heat radiation even in a dark place. In particular, the effect is great in the case of infrared spectrally sensitized light-sensitive materials in which the sensitivity is increased by a supersensitizer.

These sensitizing dyes may be used alone, or a combination thereof may be used, and the combination of sensitizing dyes is often used particularly for the purpose of supersensitizing. Along with the sensitizing dye, a dye having no spectral sensitizing effect itself or a substance that does not substantially absorb visible light and exhibits supersensitization may be included in the emulsion. Useful sensitizing dyes, combinations of dyes exhibiting supersensitization, and substances exhibiting supersensitization are RD17643 (issued in December 1978) No. 2
Page J IV, page 3, or Japanese Patent Publication Nos. 9-25500, 43-4933, and JP-A-59-19032, 59.
-192242, JP-A-5-341432 and the like.

In the present invention, a heteroaromatic mercapto compound represented by the following general formula [6] is preferred as the supersensitizer.

General formula [6] Ar ₁ -SM In the general formula [6], M is a hydrogen atom or an alkali metal atom, Ar ₁ is at least one nitrogen atom, a sulfur atom,
An aromatic ring or condensed aromatic ring residue having an oxygen atom, a selenium atom or a tellurium atom.

Preferred heteroaromatic rings are benzimidazole, naphthimidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole,
Benzoselenazole, benzoterrazole, imidazole, oxazole, pyrazole, triazole, triazine, pyrimidine, pyridazine, pyrazine, pyridine,
Purine, quinoline, or quinazoline. However, other heteroaromatic rings are also included.

The present invention also includes a disulfide compound which substantially forms the above mercapto compound when contained in a dispersion of an emulsion containing an organic acid silver salt and / or a photosensitive silver halide grain. . In particular, a disulfide compound represented by the following general formula can be mentioned as a preferable example.

[0099] In formula (7) Ar ₁ -S-S-Ar ₁ formula, Ar ₁ has the same meaning as Ar ₁ in the general formula [6].

The supersensitizer preferably used in the present invention is preferably used in the range of 0.001 to 1.0 mol per mol of silver in the sensitive layer containing the organic silver salt and the photosensitive silver halide grains. . Particularly preferably, it is 0.0 per mol of silver.
Amounts in the range 1 to 0.5 mol are preferred.

A reducing agent is incorporated in the photothermographic material of the invention. Examples of suitable reducing agents are described in US Pat. No. 3,770,
No. 448, No. 3,773,512, No. 3,59
No. 3,863 and RD17029, 29963, and there are the following. Aminohydroxycycloalkenone compounds (for example, 2-hydroxypiperidino-2-cyclohexenone); Amino reductones (for example, piperidinohexose reductone monoacetate) as a precursor of a reducing agent; N-hydroxy Urea derivative (for example, Np-
Methylphenyl-N-hydroxyurea); aldehyde or ketone hydrazones (eg, anthracene aldehyde phenylhydrazone); phosphoramidophenols; phosphoramidoanilines; polyhydroxybenzenes (eg, hydroquinone, t-butyl-hydroquinone) , Isopropylhydroquinone and (2,5-dihydroxy-phenyl) methyl sulfone); sulfhydroxamic acids (eg, benzenesulfhydroxamic acid); sulfonamide anilines (eg, 4- (N-
Methanesulfonamido) aniline); 2-tetrazolylthiohydroquinones (eg, 2-methyl-5- (1-
Phenyl-5-tetrazolylthio) hydroquinone); tetrahydroquinoxalines (eg 1,2,3,4-
Tetrahydroquinoxaline); amidooxins; azines (eg, aliphatic carboxylic acid aryl hydrazides and ascorbic acid); polyhydroxybenzene and hydroxylamine; reductone and / or hydrazine; hydroxamic acids; azines and sulfones Combination of amidophenols; α-cyanophenylacetic acid derivative; bis-β-naphthol and 1,3-
Combination of dihydroxybenzene derivatives; 5-pyrazolones; sulfonamide phenol reducing agent; 2-phenylindane-1,3-dione and the like; chroman; 1,4-dihydropyridines (eg 2,6-dimethoxy-3,
5-dicarboethoxy-1,4-dihydropyridine);
Bisphenols (for example, bis (2-hydroxy-3
-T-butyl-5-methylphenyl) methane, 2,2-
Bis (4-hydroxy-3-methylphenyl) propane, 4,5-ethylidene-bis (2-t-butyl-6-
Methyl) phenol), UV-sensitive ascorbic acid derivatives and 3-pyrazolidones. Among them, particularly preferable reducing agents are bisphenols.

The heat-developable light-sensitive material forms a photographic image by a heat-development treatment, and comprises a reducible silver source (organic silver salt), photosensitive silver halide grains, a reducing agent and, if necessary, a silver tone. It is usually preferable that the photothermographic material contains a toning agent for adjusting the color of black to a black color in a state of being dispersed in a binder matrix. The silver produced by the redox reaction of the organic silver salt and the developing agent in the exposed area by heat development thereby forms a black image. This reaction process proceeds without supplying any processing liquid such as water from the outside.

Examples of suitable toning agents used in the present invention include Research Disclosure (hereinafter, abbreviated as RD).
No. 17029, which is as follows.

Imides (eg phthalimide); Cyclic imides, pyrazolin-5-ones and quinazolinones (eg succinimide, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and 2 , 4-thiazolidinedione); naphthalimides (eg, N-hydroxy-1,8-naphthalimide); cobalt complexes (eg, cobalt hexaamminetrifluoroacetate), mercaptans (eg, 3-mercapto-1,2, 4-triazole); N
-(Aminomethyl) aryldicarboximides (eg N- (dimethylaminomethyl) phthalimide);
Blocked pyrazoles (eg, N, N'-hexamethylenebis (1-carbamoyl-3,5-dimethylpyrazole)); isothiuronium
onium) derivatives and certain photobleaching agents (eg, 1,8- (3,6-dioxaoctane) bis (isothiuronium trifluoroacetate) and 2-
(A combination of tribromomethylsulfonyl) benzothiazole); phthalazinone, a phthalazinone derivative or a metal salt of these derivatives (for example, 4- (1-naphthyl)).
Phthalazinone, 6-chlorophthalazinone, 5,7-dimethyloxyphthalazinone, and 2,3-dihydro-1,
4-phthalazinedione); a combination of phthalazinone and a sulfinic acid derivative (for example, a combination of 6-chlorophthalazinone and sodium benzenesulfinate or 8-methylphthalazinone and sodium p-trisulfonate); a combination of phthalazine and phthalic acid. Combination; phthalazine (including adduct of phthalazine) and maleic anhydride and phthalic acid, 2,3-naphthalenedicarboxylic acid or o-phenylene acid derivative and its anhydride (eg phthalic acid,
4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride) in combination with at least one compound; quinazolinediones, benzoxazine, naphthoxazine derivatives; benzoxazine-2,4-diones ( For example, 1,3-benzoxazine-2,4-dione); pyrimidines and asymmetric triazines (for example, 2,4-dihydroxypyrimidine) and tetraazapentalene derivatives (for example, 3,6-dimercapto-1, 4-diphenyl-1H, 4H-2, 3a,
5,6a-Tetraazapentalene). Among these, phthalazinone or phthalazine is particularly preferable as a toning agent.

An antifoggant may be contained in the photothermographic material of the invention. For example, US Pat. No. 3,589,90
The mercury compounds known from No. 3 and the like are known as effective antifoggants, but are not environmentally preferable. Therefore, non-mercury antifoggants have been studied for a long time.
Non-mercury antifoggants include, for example, US Pat.
46,075, 4,452,885, JP-A-5
Antifoggants such as those disclosed in 9-57234 are preferred.

Particularly preferred non-mercury antifoggants are US Pat. Nos. 3,874,946 and 4,756,99.
A compound as disclosed in No. 9, --C (X ₁ ).
(X ₂ ) (X ₃ ) (where X ₁ and X ₂ are halogen atoms and X
₃ is a heterocyclic compound having one or more substituents represented by hydrogen atoms or halogen atoms). As examples of suitable antifoggants, compounds described in JP-A No. 9-288328, paragraph numbers [0030] to [0036] are preferably used.

Further, as another preferable example of the antifoggant, JP-A-9-90550, paragraph No. [006] is used.
2] to [0063]. In addition, other suitable antifoggants are disclosed in US Pat.
28,523 and EP 600,587, EP 605,981 and EP 631,176.

Binders suitable for the photothermographic material of the present invention are transparent or translucent and generally colorless, and include natural polymers such as synthetic resins, polymers and copolymers, and other film forming media such as: gelatin, gum arabic, and poly. (Vinyl alcohol), hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, poly (vinylpyrrolidone), casein, starch, polyacrylic acid, polymethylmethacrylic acid, polyvinyl chloride, polymethacrylic acid, copoly (styrene-maleic anhydride) ), Copoly (styrene-acrylonitrile), copoly (styrene-butadiene), polyvinyl acetals (eg, polyvinyl formal and polyvinyl butyral), polyesters, polyurethanes,
Examples include phenoxy resin, polyvinylidene chloride, polyepoxides, polycarbonates, polyvinyl acetate, cellulose esters, and polyamides.

It may be hydrophilic or hydrophobic, but in the present invention, it is preferable to use a hydrophobic transparent binder in order to enhance heat developability and to reduce fog after heat development.

Preferred binders include polyvinyl butyral, cellulose acetate, cellulose acetate butyrate, polyester, polycarbonate, polyacrylic acid, polyurethane and the like.

Among them, polyvinyl butyral, cellulose acetate, cellulose acetate butyrate and polyester are particularly preferably used.

Further, in order to protect the surface of the photothermographic material and prevent scratches, a non-photosensitive layer may be provided above the photothermographic layer. The binder used in these non-photosensitive layers may be of the same type or different types as the binder used in the photothermographic layer.

In the present invention, the binder amount in the photosensitive layer is preferably 1.5 to 6 g / m ² .

It is more preferably 1.7 to 5 g / m ² . If it is less than 1.5 g / m ² , the density of the unexposed area may increase significantly and it may not be usable.

In the present invention, it is preferable to include a matting agent in both the backing layer and the protective layer. In order to improve the repeatability of the dimension of the present invention, a polymer matting agent or an inorganic matting agent is added to the whole emulsion layer side. It is preferable to contain 0.5 to 10% by mass of the binder.

The material of the matting agent preferably used in the present invention may be either an organic substance or an inorganic substance.

For example, as the inorganic substance, Swiss Patent No. 3 can be used.
Silica described in 30,158, etc., French Patent No. 1,29
Glass powder described in US Pat. No. 6,995, British Patent No. 1,17
Alkaline earth metals described in No. 3,181 or carbonates such as cadmium and zinc can be used as a matting agent. Organic substances include US Pat. No. 2,322,03
No. 7, etc., starch derivatives, such as Belgian Patent No. 625,451 and British Patent No. 981,198, polyvinyl alcohols described in Japanese Patent Publication No. 44-3643, Swiss Patent No. 330,158. Or polymethacrylate described in U.S. Pat.
Organic matting agents such as polyacrylonitrile described in US Pat. No. 079,257 and polycarbonate described in US Pat. No. 3,022,169 can be used.

The shape of the matting agent may be either a fixed shape or an amorphous shape, but a fixed shape is preferable, and a spherical shape is preferably used. The size of the matting agent is represented by the diameter when the volume of the matting agent is converted into a spherical shape. In the present invention, the particle size of the matting agent refers to the spherically converted diameter.

The matting agent preferably used in the present invention is
The average particle size is preferably 0.5 μm to 10 μm, more preferably 1.0 μm to 8.0 μm.
Further, the coefficient of variation of the particle size distribution is preferably 50% or less, more preferably 40% or less, and particularly preferably 30% or less.

Here, the coefficient of variation of the particle size distribution is a value represented by the following formula. (Standard deviation of particle size) / (average value of particle size) × 100 The matting agent may be contained in any constituent layer, but in order to achieve the object of the present invention, it is preferably a constituent layer other than the photosensitive layer. And more preferably the outermost layer as viewed from the support.

The matting agent may be added by dispersing it in the coating solution in advance, or by spraying the matting agent after the coating solution is applied and before the drying is completed. Good. When adding a plurality of types of matting agents, both methods may be used in combination.

The photothermographic material of the present invention is stable at room temperature, but it is subjected to development treatment by heating to high temperature after exposure. In the present invention, the heating temperature is 100 ° C to 15 ° C.
The feature is that development processing is performed at 0 ° C. If the temperature is less than 100 ° C, a sufficient image density cannot be obtained in a short time, and
If the temperature exceeds ℃, the binder will melt and transfer to the roller will adversely affect the image itself and the transportability.
This is not preferable because min increases.

By heating, silver is produced through a redox reaction between an organic silver salt (which functions as an oxidizing agent) and a reducing agent. This redox reaction is promoted by the catalytic action of the latent image generated on the silver halide upon exposure.

The silver produced by the reaction of the organic silver salt in the exposed areas provides a black image, which contrasts with the unexposed areas and is imaged. This reaction process proceeds without supplying a treatment liquid such as water from the outside.

The photothermographic material of the present invention has a photosensitive layer on both sides of a support. Although only the photosensitive layer may be formed on the support, it is preferable to form the non-photosensitive layer on the photosensitive layer.

A filter layer may be formed to control the amount or wavelength distribution of light passing through the photosensitive layer, or the photosensitive layer may contain a dye or a pigment. The photosensitive layer may be composed of a plurality of layers, and the sensitivity may be a high sensitive layer / low sensitive layer or a low sensitive layer / high sensitive layer for adjusting gradation. Various additives may be added to any of the light-sensitive layer, the non-light-sensitive layer, and other forming layers.

The photothermographic material of the present invention may contain, for example, a surfactant, an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber and a coating aid.

The exposure wavelength of the present invention is 770 nm to 1100.
nm, preferably 780 nm to 850 nm.

For example, when the light-sensitive material is made to be sensitive to infrared light, it can be applied to any light source in the infrared light range, but the laser power is high and the light-sensitive material is transparent. Infrared semiconductor lasers (780 nm, 820 nm) are more preferably used from the viewpoints that they can be obtained.

The first aspect is the invention of claim 6 of the present invention, which is a method of using a laser scanning exposure machine in which the angle formed by the scanning laser beam and the exposure surface of the photosensitive material is not substantially vertical.

Here, "not to be substantially vertical" means an angle which is the most vertical during laser scanning, preferably 55 to 88 degrees, more preferably 60 to 86 degrees.
Degree, more preferably 65 to 84 degrees, and most preferably 7 degrees.
It means 0 to 82 degrees.

The second is the method according to the invention of claim 5 of the present invention, in which the exposure is carried out by using a laser scanning exposure machine which emits scanning laser light of a longitudinal multi type. Compared with scanning laser light of a vertical single mode, these reduce image quality deterioration such as occurrence of interference fringe-like unevenness.

Further, the third method is a preferable method of the present invention, in which two or more lasers are used to form an image by scanning exposure.

Such an image recording method using a plurality of lasers is used in an image writing means of a laser printer or a digital copying machine for writing an image for each plural lines in one scanning because of the demand for higher resolution and higher speed. This is a known technique and is known, for example, from Japanese Patent Application Laid-Open No. 60-166916. This is a method in which a laser beam emitted from a light source unit is deflected and scanned by a polygon mirror and an image is formed on a photoconductor through an fθ lens or the like. This is the same laser scanning optics in principle as a laser imager. It is a device.

In each of the image recording methods described above,
Lasers used for scanning exposure are generally well known solid-state lasers such as ruby lasers, YAG lasers, glass lasers; He-Ne lasers, Ar ion lasers, and K lasers.
r-ion laser, CO ₂ laser, CO laser, He-C
Gas laser such as d laser, N ₂ laser, excimer laser; InGaP laser, AlGaAs laser, GaAs
P laser, InGaAs laser, InAsP laser, C
Semiconductor lasers such as dSnP ₂ laser and GaSb laser;
A chemical laser, a dye laser, or the like can be appropriately selected and used according to the application, but among these, it is preferable to use a semiconductor laser having a wavelength of 600 to 1200 nm from the viewpoint of maintenance and the size of the light source.

In a laser used in a laser imager or a laser imagesetter, the beam spot diameter on the exposure surface during scanning exposure is generally 5 to 75 μm as the minor axis diameter and 5 to 100 μm as the major axis diameter. The laser beam scanning speed can be set to an optimum value for each photosensitive material by the sensitivity and laser power at the laser oscillation wavelength peculiar to the photothermographic material.

[0137]

The present invention will be specifically described below with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1 [Preparation of undercoated photographic support] <Preparation of PET undercoated photographic support> Commercially available biaxially stretched and thermally fixed 175 μm thick optical density of 0.170
8 W / m ^{2 on} both sides of the PET film colored in blue (measured with Konica Densitometer PDA-65)
・ Corona discharge treatment for minutes is applied, and one side of the following undercoating coating solution a-1 is applied to a dry film thickness of 0.8 μm and dried to form an undercoating layer A-1. The undercoating coating solution b-1 described below was applied to the surface so as to have a dry film thickness of 0.8 μm, and dried to form an undercoating layer B-1.

<< Undercoating Liquid a-1 >> Butyl acrylate (30% by mass) t-Butyl acrylate (20% by mass) Styrene (25% by mass) 2-Hydroxyethyl acrylate (25% by mass) Copolymer latex liquid (Solid content 30%) 270 g (C-1) 0.6 g Hexamethylene-1,6-bis (ethylene urea) 0.8 g Finish with water to 1 L << Subbing coating liquid b-1 >> Butyl acrylate (40% by mass) ) Styrene (20 mass%) Glycidyl acrylate (40 mass%) Copolymer latex liquid (solid content 30%) 270 g (C-1) 0.6 g Hexamethylene-1,6-bis (ethylene urea) 0.8 g After finishing to 1 L with water, on the upper surface of the undercoat layer A-1 and the undercoat layer B-1,
A corona discharge of 8 W / m ² · min was applied, and the following undercoating upper layer coating liquid a-2 was dried to a thickness of 0.1 μm on the undercoating layer A-1.
As the undercoating upper layer A-2, the following undercoating upper layer coating liquid b-2 is provided on the undercoating layer B-1 to have an antistatic function so that the dry film thickness becomes 0.8 μm. It was applied as B-2.

<< Undercoating Upper Layer Coating Liquid a-2 >> Gelatin 0.4 g / m ² Mass (C-1) 0.2 g (C-2) 0.2 g (C-3) 0.1 g Silica particles ( Average particle size 3 μm) 0.1 g Finish with water to 1 L << Undercoating upper layer coating liquid b-2 >> (C-4) 60 g Latex liquid containing (C-5) as a component (solid content 20%) 80 g Ammonium sulfate 0. 5g (C-6) 12g Polyethylene glycol (weight average molecular weight 600) 6g Finish with water to 1L

[0141]

[Chemical 10]

[0142]

[Chemical 11]

<< Backside coating >> While stirring 830 g of methyl ethyl ketone (MEK), cellulose acetate butyrate (Eastman Chemical Co.,
CAB381-20) 84.2 g and polyester resin (Bostic, VitelPE2200B) 4.
5 g was added and dissolved. Next, add 0.3 to the dissolved liquid.
0 g of Infrared Dye 1 was added and methanol 43.2 was added.
F-based activator dissolved in g (Asahi Glass Co., Surflon KH4
0) 4.5 g and F-type activator (Megafag F120K, Dainippon Ink and Chemicals, Inc.) 2.3 g were added and sufficiently stirred until they were dissolved. Finally, silica dispersed in methyl ethyl ketone at a concentration of 1 mass% by a dissolver type homogenizer (WR Grace, Syroid 64X600).
0) of 75 g was added and stirred to prepare a coating liquid for the back surface side.

The back surface coating liquid thus prepared was
It was applied by an extrusion coater and dried so that the dry film thickness was 3.5 μm. Drying temperature 100 ℃, dew point temperature 1
It was dried for 5 minutes using a drying air of 0 ° C.

<< Preparation of Photosensitive Silver Halide Emulsion A >> A1 Phenylcarbamoylated gelatin 88.3 g Compound (A) (10% aqueous methanol solution) 10 ml Potassium bromide 0.32 g Water to make 5429 ml B1 0.67 mol / L Aqueous silver nitrate solution 2635 ml C1 Potassium bromide 51.55 g Potassium iodide 1.47 g Finish with water to 660 ml D1 Potassium bromide 154.9 g Potassium iodide 4.41 g Iridium chloride (1% solution) 0.93 ml Finish with water to 1982 ml E1 0.4 mol / L aqueous potassium bromide solution The following silver potential control amount F1 potassium hydroxide 0.71 g finished with water to 20 ml G1 56% acetic acid aqueous solution 18.0 ml H1 anhydrous sodium carbonate 1.72 g finished with water to 151 ml Compound (A) : HO (CH ₂ C _{2 O) n - (CH (} CH 3) CH 2 O) 17 - (CH 2 CH 2 O) m H (m + n = 5~7) Japanese Patent Publication No. 58-58288, mixing and stirring machine shown in Nos. 58-58289 Solution (B1) to solution (A1) using
1/4 amount and the total amount of the solution (C1) at a temperature of 30 ° C and pAg
While controlling at 8.09, the mixture was added for 4 minutes and 45 seconds by the simultaneous mixing method to perform nucleation. After 1 minute, the solution (F
The whole amount of 1) was added. During this period, the pAg was adjusted by the solution (E
This was appropriately performed using 1). After 6 minutes, solution (B1)
Of 3/4 and the total amount of the solution (D1) at a temperature of 30 ° C., p
While controlling to Ag 8.09, it was added over 14 minutes and 15 seconds by the double-blending method. After stirring for 5 minutes, the temperature was raised to 40 ° C., the entire amount of the solution (G1) was added, and the silver halide emulsion was precipitated. The supernatant was removed, leaving 2000 ml of the sedimented portion, 10 liters of water was added, and after stirring, the silver halide emulsion was sedimented again. The supernatant is removed, leaving 1500 ml of the sedimented portion, and 10 liters of water is further added.
After stirring, the silver halide emulsion was allowed to settle. Settling part 15
After removing the supernatant liquid leaving 00 ml, the solution (H
1) was added, the temperature was raised to 60 ° C., and the mixture was further stirred for 120 minutes.
Finally, the pH was adjusted to 5.8 and water was added so that the amount of silver was 1161 g per mol of silver to obtain a photosensitive silver halide emulsion A.

The photosensitive silver halide grains in this photosensitive silver halide emulsion A are monodisperse cubic silver iodobromide having an average grain size of 0.040 μm, a grain size variation coefficient of 12% and a [100] plane ratio of 92%. It was a particle.

<< Preparation of Photosensitive Silver Halide Emulsion B >> The photosensitive silver halide in the photosensitive silver halide emulsion was prepared in the same manner except that the mixing temperature of the photosensitive silver halide emulsion A was changed to 45 ° C. A photosensitive silver halide emulsion B having an average grain size of 0.058 μm was obtained.

<< Preparation of Photosensitive Silver Halide Emulsion C >> The photosensitive silver halide in the photosensitive silver halide emulsion was prepared in the same manner except that the mixing temperature of the photosensitive silver halide emulsion A was changed to 60 ° C. A photosensitive silver halide emulsion C having an average grain size of 0.080 μm was obtained.

<< Preparation of powdered organic silver salt A >> 130.8 g of behenic acid and 67.7 of arachidic acid were added to 4720 ml of pure water.
g, stearic acid 43.6 g, and palmitic acid 2.3 g were dissolved at 80 ° C. Next, 540.2 ml of a 1.5 mol / L sodium hydroxide aqueous solution was added, and 6.9 ml of concentrated nitric acid was added.
Was added and then cooled to 55 ° C. to obtain a fatty acid sodium solution. While maintaining the temperature of the sodium fatty acid solution at 55 ° C., 45.3 g of the above photosensitive silver halide emulsion A and 450 ml of pure water were added and stirred for 5 minutes.

Next, a 1 mol / L silver nitrate solution 702.6 was used.
ml was added over 2 minutes and stirred for 10 minutes to obtain an organic silver salt dispersion. After that, the obtained organic silver salt dispersion was transferred to a water washing container, deionized water was added thereto, and the mixture was stirred and then allowed to stand to separate the organic silver salt dispersion by flotation to remove the water-soluble salts below. After that, washing with deionized water and drainage were repeated until the conductivity of the drainage reached 2 μs / cm, and after centrifugal dehydration was performed, the cake-shaped organic silver salt obtained was dried with a flash dryer flash jet dryer (stock (Manufactured by Seishin Enterprise Co., Ltd.) was dried until the water content became 0.1% under the operating conditions of nitrogen gas atmosphere and hot air temperature at the entrance of the dryer to obtain dried organic silver salt A of organic silver salt.

An infrared moisture meter was used to measure the water content of the organic silver salt composition. << Preparation of Preliminary Photosensitive Solution A >> Polyvinyl butyral powder (M
Onsanto, Butvar B-79) 14.
57g was dissolved in 1457g of methyl ethyl ketone,
A-GETZMANN Dissolver DISPERMA
Powdered organic silver salt A5 while stirring with TCA-40M type
A preliminary photosensitive solution A was prepared by gradually adding 00 g and thoroughly mixing them.

<< Preparation of Photosensitive Emulsion Solution 1 >> Preliminary Photosensitive Solution A was pumped into a zirconia bead having a diameter of 0.5 mm (Toray's Treceram) so that the residence time in the mill would be 1.5 minutes. 80% filled media type disperser DIS
PERMAT SL-C12EX type (VMA-GETZ
(Manufactured by Mann) and dispersed at a mill peripheral speed of 8 m / s to prepare a photosensitive emulsion liquid 1.

<< Preparation of Photosensitive Emulsion Solution 2 >> Using Photosensitive Silver Halide Emulsion B, Photosensitive Emulsion Solution 2 was prepared in the same manner as in Photosensitive Emulsion Solution 1.

<< Preparation of Photosensitive Emulsion Solution 3 >> Using Photosensitive Silver Halide Emulsion C, Photosensitive Emulsion Solution 3 was prepared in the same manner as in Photosensitive Emulsion Solution 1.

<< Preparation of Addition Solution of Compound of General Formula (1) >>
An additive solution was prepared by dissolving the compound of the general formula (1) in methanol to a concentration of 1% by mass.

<< Preparation of Stabilizer Solution >> 1.0 g of stabilizer 1,
0.31 g of potassium acetate was dissolved in 4.97 g of methanol to prepare a stabilizer solution.

<< Preparation of Infrared Sensitizing Dye Liquid A >> 19.2 mg
Infrared sensitizing dye S-1, 1.488 g of 2-chloro-benzoic acid, 2.779 g of Stabilizer 2 and 365 mg of 5.
-Methyl-2-mercaptobenzimidazole 31.
Infrared sensitizing dye solution A was prepared by dissolving in 3 ml of MEK in the dark.

<< Preparation of Additive Liquid a >> 1,1-as a developer
Bis (2-hydroxy-3,5-dimethylphenyl)-
27.98 g of 2-methylpropane and 1.54 g of 4-
Methylphthalic acid, 0.48 g of the above infrared dye 1 was added to MEK
It was dissolved in 110 g to obtain an additive liquid a.

<< Preparation of Additive Solution b >> 3.56 g of antifoggant 2, 3.43 g of phthalazine was dissolved in 40.9 g of MEK to prepare Additive Solution b.

<< Preparation of Photosensitive Layer Coating Solution A >> In an inert gas atmosphere (nitrogen 97%), the above-mentioned photosensitive emulsion solution 1 (5
0 g) and MEK 15.11 g with stirring at 21 ° C.
Keep it warm to prevent fog 1 (10% methanol solution) 3
90 μl was added and stirred for 1 hour.

Further, 494 μl of calcium bromide (10% methanol solution) was added and stirred for 20 minutes. continue,
After adding 167 ml of the stabilizer solution and stirring for 10 minutes,
1.32 g of the infrared sensitizing dye solution A was added and stirred for 1 hour.

Then, the temperature was lowered to 13 ° C., and the mixture was stirred for another 30 minutes, and polyvinyl butyral (Butvar B-79, Monsanto Co.) was kept at 13 ° C.
After adding 13.31 g and stirring for 30 minutes, 1.084 g of tetrachlorophthalic acid (9.4 mass% MEK solution) was added and stirred for 15 minutes. While continuing to stir,
12.43 g of additive liquid a, 1.6 ml of Desmodu
rN3300 / Mobey's aliphatic isocyanate (10% MEK solution), 4.27 g of Additive solution b was sequentially added and stirred to obtain a photosensitive layer coating solution A.

<< Preparation of Photosensitive Layer Coating Solution B >> Photosensitive Emulsion Solution 2
A photosensitive layer coating liquid B was prepared in the same manner as the photosensitive layer coating liquid A except that

<< Preparation of Photosensitive Layer Coating Liquid C >> In an inert gas atmosphere (nitrogen 97%), the photosensitive emulsion liquid 1 (5
0 g) and MEK 15.11 g with stirring at 21 ° C.
Keep it warm to prevent fog 1 (10% methanol solution) 3
90 μl was added and stirred for 1 hour. Further, add 494 μl of calcium bromide (10% methanol solution) to 20
Stir for minutes.

Subsequently, 167 ml of the stabilizer solution was added to 1
After stirring for 0 minutes, 1.32 g of the infrared sensitizing dye solution A
Was added and stirred for 1 hour. Then, the temperature is lowered to 13 ° C., and the mixture is stirred for another 25 minutes, then, a methanol solution of the compound of the general formula (1) is added so that the kind and the addition amount in Table 1 are reached, and after 5 minutes, the temperature is kept at 13 ° C. As it is, polyvinyl butyral (Monsanto's Butvar B
-79) After adding 13.31 g and stirring for 30 minutes, tetrachlorophthalic acid (9.4 mass% MEK solution) 1.0
84 g was added and stirred for 15 minutes. With further stirring, 12.43 g of the additive liquid a and 1.6 ml of Des
modur N3300 / Mobey's aliphatic isocyanate (10% MEK solution), 4.27 g of additive liquid b
Was sequentially added and stirred to obtain a photosensitive layer coating liquid C.

<< Preparation of Photosensitive Layer Coating Solution D >> Photosensitive Emulsion Solution 2
Was used to prepare a photosensitive layer coating liquid D in the same manner as the photosensitive layer coating liquid C.

<< Preparation of Photosensitive Layer Coating Solution E >> Photosensitive Emulsion Solution 3
Was used to prepare a photosensitive layer coating liquid E in the same manner as the photosensitive layer coating liquid C.

<< Preparation of Matting Agent Dispersion >> Cellulose acetate butyrate (Eastman Chemical)
Company, 7.5 g of CAB171-15) to MEK42.5
g of calcium carbonate (Specia)
Light Minerals, Super-Pfle
x200) (5 g) was added, and the mixture was dispersed with a dissolver type homogenizer at 8000 rpm for 30 min to prepare a matting agent dispersion liquid.

<< Preparation of Light-Sensitive Silver Halide Emulsion D >> The light-sensitive silver halide emulsion in the light-sensitive silver halide emulsion was prepared in the same manner except that the mixing temperature of the light-sensitive silver halide emulsion A was changed to 20 ° C. The minimum average particle size of the particles is 0.0
A 3 μm photosensitive silver halide emulsion D was obtained.

<< Preparation of Photosensitive Emulsion Solution 4 >> Using Photosensitive Silver Halide Emulsion D, Photosensitive Emulsion Solution 4 was prepared in the same manner as in Photosensitive Emulsion Solution 1.

<< Preparation of Photosensitive Layer Coating Solution F >> Photosensitive Emulsion Solution 4
Was used to prepare a photosensitive layer coating liquid F in the same manner as the photosensitive layer coating liquid C.

<< Preparation of Photosensitive Silver Halide Emulsion G >> A photosensitive silver halide emulsion in a photosensitive silver halide emulsion is prepared in the same manner except that the mixing temperature of the photosensitive silver halide emulsion A is 70 ° C. The maximum particle size of the average particle size of the particles is 0.0
A photosensitive silver halide emulsion G of 9 μm was obtained.

<< Preparation of Photosensitive Emulsion Solution 5 >> Using Photosensitive Silver Halide Emulsion G, Photosensitive Emulsion Solution 5 was prepared in the same manner as in Photosensitive Emulsion Solution 1.

<< Preparation of Photosensitive Layer Coating Solution G >> Photosensitive Emulsion Solution 5
Was used to prepare a photosensitive layer coating liquid G in the same manner as the photosensitive layer coating liquid C.

<< Preparation of Surface Protective Layer Coating Liquid >> Cellulose acetate butyrate (Eastman Chemical) was stirred while stirring 865 g of MEK (methyl ethyl ketone).
Al, CAB171-15) 96 g, polymethylmethacrylic acid (Rohm & Haas, Paraloid A-21)
4.5 g and vinyl sulfone compound (HD-1) 1.
5 g, 1.0 g of benztriazole and 1.0 g of F type activator (Surflon KH40, Asahi Glass Co., Ltd.) were added and dissolved.

Next, 30 g of the above-mentioned matting agent dispersion liquid was added and stirred to prepare a surface protective layer coating liquid.

[0177]

[Chemical 12]

[0178]

[Chemical 13]

The above-mentioned photosensitive layer coating solutions were mixed in the proportions shown in Table 1 and coated on the photosensitive layer side by the following method.

<< Coating on Photosensitive Layer Surface Side >> Photosensitive materials 1 to 12 were prepared by simultaneously coating the photosensitive layer coating liquid and the surface protective layer coating liquid in layers using the extrusion coater shown in FIG. The photosensitive layer was coated with a coating amount of silver of 1.3 g / m ² , and the surface protective layer was coated with a dry film thickness of 2.5 μm.
It was done as follows. After that, the drying temperature 75 ℃,
Drying was performed for 10 minutes using a drying air with a dew point temperature of 10 ° C.

[0181]

[Table 1]

<< Exposure and Development Processing >> From the emulsion side of the light-sensitive material prepared as described above, a wavelength of 800
The exposure was performed by laser scanning with an exposure device using a semiconductor laser having a vertical multimode of nm to 820 nm as an exposure source. At this time, an image was formed by setting the angle between the exposed surface of the photosensitive material and the exposure laser beam to 75 degrees. (Note that an image with less unevenness and unexpectedly good sharpness was obtained compared to when the angle was 90 degrees.) After that, the photosensitive material was protected using an automatic processor having a heat drum. Heat development was carried out at 125 ° C. for 15 seconds so that the layer was in contact with the drum surface. At that time, exposure and development are at 23 ° C and 50% RH
I went to a humid room. The obtained image was evaluated with a densitometer. The result of the measurement is the sensitivity (the reciprocal of the ratio of the exposure dose that gives a density 1.0 higher than that of the unexposed portion), the fog
The sample No. was evaluated by Dmax and gamma. 1 sensitivity is 10
The relative values of 0 are shown in Table 2.

<< Evaluation of Silver Tone >> For evaluation of silver tone,
Exposure and development were performed so that the density after development was 1.1 ± 0.05. This sample has a color temperature of 7700 Kelvin and an illuminance of 116.
Light source of 00 lux for 10 hours, 100 hours, 1000
It was irradiated for an hour and the color tone of silver was evaluated according to the following criteria. It should be noted that the rank with no problem in quality assurance is 4 or higher.

Evaluation criteria 5: Pure black tone with no yellowness 4: Not pure black, but almost no yellowness 3: Partially slightly yellowish 2: A slight yellowishness is felt on the entire surface 1: At first glance, a yellowish color is felt.

The results are shown in Table 2. << Evaluation of uneven density >> Using the sample used for the evaluation of silver tone,
The uniformity of the in-plane density was visually evaluated.

Ranks with no problem in quality assurance are 3 or higher. Evaluation Criteria 4: Density is uniform over the entire surface and no unevenness is observed.

3: Slight unevenness is observed, but there is no problem in practical use 2: Unevenness is observed on the entire surface, but the degree is weak 1: Very strong unevenness is observed on the entire surface, which is not suitable for practical use.

The results are shown in Table 2.

[0189]

[Table 2]

[0190]

As demonstrated in the examples, the photothermographic material, the image recording method and the processing method according to the present invention have a low contrast and a wide exposure latitude and are excellent in the maximum density, minimum density and image quality of an image. Have an effect.

[Brief description of drawings]

FIG. 1 is a schematic structural diagram of an extrusion coater used in the present invention.

Claims (7)

[Claims] 1. A photothermographic material containing a light-sensitive silver halide emulsion, an organic silver salt, a reducing agent and a binder, wherein the light-sensitive silver halide grains in the light-sensitive silver halide emulsion are the organic silver salts. Which is formed independently of each other, contains two or more kinds of photosensitive silver halide grains having different average grain sizes, and contains a compound represented by the following general formula (1). Photographic material. [Chemical 1] (In the formula, Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group, T ₃₁ represents a divalent linking group or a linking group consisting of an aliphatic hydrocarbon group, and J ₃₁ represents an oxygen atom, a sulfur atom or Represents a divalent linking group or linking group containing at least one nitrogen atom, wherein Ra, Rb, Rc and Rd each represent a hydrogen atom, an acyl group, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group; , Ra and Rb, Rc and Rd, Ra and Rc or Rb and Rd can be bonded to each other to form a nitrogen-containing heterocyclic group, M ₃₁ represents an ion necessary for canceling the charge in the molecule. , K31 represents the number of ions necessary to cancel the charge in the molecule.) 2. The maximum grain size of the two or more types of photosensitive silver halide grains having different average grain sizes is from 0.06 μm to
0.09 μm, and the minimum particle size is 0.03 μm
The photothermographic material according to claim 1, which has a thickness of 0.05 μm. 3. The total amount of silver is 0.5 g / m ^{2 to} 1.5 g / m ^2.
The photothermographic material according to claim 1 or 2, wherein 4. An exposure wavelength of 770 nm to 11 using the photothermographic material according to claim 1.
An image recording method comprising exposing with a scanning laser beam of 00 nm. 5. The image recording method according to claim 4, wherein the scanning laser light is exposed by a laser light scanning exposure device having a vertical multi-type. 6. The image recording method according to claim 4, wherein exposure is performed by a laser beam scanning exposure device in which an angle formed by the scanning laser beam is not substantially vertical. 7. A processing method, which comprises processing the photothermographic material according to claim 1 at a developing temperature of 100 ° C. to 150 ° C.